Inks

ABSTRACT

A composition comprising:  
     a) 0.1 to 30 parts of colorant;  
     b) 0.1 to 20 parts of a compound of Formula (1):  
     R 1 R 2 N—Ar—(SO 3 X) n   Formula ( 1 )  
     wherein:  
     R 1  is H, alkyl, cycloalkyl or aralkyl and R 2  is alkyl, cycloalkyl or aralkyl; or  
     R 1  and R 2 , together with the N atom to which they are attached, form a 5- or 6-membered ring;  
     Ar is phenylene or naphthylene;  
     X is H or a cation; and  
     n is 1 or 2;  
     c) 1 to 40 parts of organic solvent;  
     d) 0 to 20 parts of hydrotropic agent;  
     e) 0 to 5 parts of biocide;  
     f) 0 to 5 parts of surfactant; and  
     g) 1 to 98.8 parts of water;  
     wherein all parts are by weight and a)+b)+c)+d)+e)+f)+g) add up to 100. Also claimed are inks comprising these compositions, ink jet printer cartridges containing these inks, their use in ink jet printing especially where the temperature of application is greater than 30° C. and substrates printed with these compositions or inks.

[0001] This invention relates to inks, to printing processes, to printedsubstrates and to ink-jet printer cartridges.

[0002] Ink-jet Printing (“IJP”) is a non-impact printing technique inwhich droplets of ink are ejected through a fine nozzle onto a substratewithout bringing the nozzle into contact with the substrate. There aremany demanding performance requirements for inks used in IJP. Forexample they desirably provide sharp, non-feathered images having goodwater-fastness, light-fastness and optical density. The inks are oftenrequired to dry quickly when applied to a substrate to prevent smudging,but they should not form a crust over the tip of an inkjet nozzlebecause this will stop the printer from working. The inks should also bestable to storage over time without decomposing or forming a precipitatewhich could block the fine nozzle. Stability is a particular issue whenjetting is performed at temperatures in excess of 30° C. where problemscan arise, especially with regard to pH drift which in turn results indestabilisation of the ink formulation leading to problems such ascrystallisation and colour shift.

[0003] Inks containing reactive dyes for use in textile ink-jet printingare known from U.S. Pat. No. 5,403,358. The inks are buffered to pH 5 to8 using the sodium salt of metanilic acid (i.e. aniline-3-sulphonicacid) or an alkali metal phosphate.

[0004] According to a first aspect of the present invention there isprovided a composition comprising:

[0005] a) 0.1 to 30 parts of colorant;

[0006] b) 0.1 to 20 parts of a compound of Formula (1):

R¹R²N—Ar—(SO₃X)_(n)  Formula (1)

[0007] wherein:

[0008] R¹ is H, alkyl, cycloalkyl or aralkyl and R² is alkyl, cycloalkylor aralkyl; or

[0009] R¹ and R², together with the N atom to which they are attached,form a 5- or 6-membered ring;

[0010] Ar is phenylene or naphthylene;

[0011] X is H or a cation; and

[0012] n is 1 or 2;

[0013] c) 1 to 40 parts of organic solvent;

[0014] d) 0 to 20 parts of hydrotropic agent;

[0015] e) 0 to 5 parts of biocide;

[0016] f) 0 to 5 parts of surfactant; and

[0017] g) 1 to 98.8 parts of water;

[0018] wherein all parts are by weight and a)+b)+c)+d)+e)+f)+g) add upto 100.

[0019] a) The Colorant

[0020] Preferably the colorant comprises a dye. Preferred dyes are azo,anthraquinone, pyrroline, phthalocyanine, polymethine, aryl-carbonium,triphenodioxazine, diarylmethane, triarylmethane, anthraquinone,phthalocyanine, methine, polymethine, indoaniline, indophenol, stilbene,squarilium, aminoketone, xanthene, fluorone, acridene, quinolene,thiazole, azine, nigrosine, oxazine, thiazine, indigoid quinonioid,quinacridone, lactone, pyrroline, benzodifuranone, or indolene dyes andmixtures thereof. Preferred azo dyes are monoazo, disazo and trisazodyes.

[0021] Preferably the dye is a reactive dye, more preferably a dyehaving a reactive group selected from halotriazine (especially mono- ordi-chloro or fluorotriazine), vinyl sulphone, groups convertible tovinyl sulphone on treatment with aqueous alkali (especiallyβ-sulphatoethyl sulphonyl) and halo pyrimidine (especially1,3,4-trichloro pyrimidin-2-yl, 1,3-difluoro4-chloropyrimidin-2-yl and1-(SO₂CH₃)-3-methyl-4-chloropyrimidin-2-yl).

[0022] Examples of reactive dyes include C.I. Reactive Black 1, 2, 3, 4,5, 6, 7, 8, 9, 19, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,42, 43, 44, 45, 46, 47; C.I. Reactive Blue 1, 2, 3, 4, 5, 6, 7, 8, 9,19, 11, 12, 13, 14, 15, 15.1, 16, 17, 18, 19, 19.2, 20, 21, 22, 23, 24,25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 36.1, 37, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76,77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94,95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109,110, 111, 112, 113, 114, 115, 116, 117, 118, 118.1, 119, 120, 121, 122,123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136,137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150,151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164,165, 166, 167, 168, 169, 170, 171, 171.1, 172, 173, 174, 175, 176, 177,178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191,192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205,206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233,234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247,248, 249, 250, 251, 252, 253, 254, 255, 256; C.I. Reactive Brown 1, 2,3, 4, 5, 6, 7, 8, 9, 19, 11, 12, 13, 14, 15, 16, 16.1, 17, 18, 19, 20,21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,39, 40, 41, 42, 43, 44, 45, 46, 47, 48; C.I. Reactive Green 1, 2, 3, 4,5, 6, 7, 8, 9, 19, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 26, 27, 28, 29, 30; C.I. Reactive Orange 1, 2, 3, 4, 5, 6, 7, 8,9, 19, 11, 12, 13, 14, 15, 15.1, 16, 16.1, 16.2, 17, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72.1, 73, 74, 75,76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93,94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108,109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 118.1, 119, 120, 121,122, 123, 124, 125, 126, 127; C.I. Reactive Red 1, 1.1, 2, 3, 3.1, 4, 5,6, 6.1, 7, 8, 8.1, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,21.1, 22, 22.1, 23, 24, 24.1, 25, 26, 27, 28, 29, 30, 31, 31.1 32, 33,34, 35, 35.1, 35.2, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 45.1, 46,47, 48, 49, 50, 51, 51.1, 52, 53, 54, 55, 56, 57, 58, 59, 60, 60.1, 61,61.1, 62, 63, 63.1, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 73.1 74, 75,76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93,94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 106.1, 107,108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 118.1, 119, 120,121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134,135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148,149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162,163, 164, 165, 166, 167, 168, 169, 170, 171, 171.1, 172, 173, 174, 175,176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189,190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203,204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217,218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231,232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259,260, 261, 262; C.I. Reactive Violet 1, 2, 3, 4, 5, 6, 7, 8, 9, 19, 11,12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46; C.I.Reactive Yellow 1, 2, 3, 4, 5, 6, 7, 8, 9, 19, 11, 12, 13, 14, 15, 15.1,16, 17, 18, 19, 20, 21, 22, 23, 24, 24.1, 25, 26, 27, 28, 29, 30, 31,32, 33, 34, 35, 36, 36.1, 37, 37.1, 38, 39, 40, 41, 42, 42.1, 43, 44,45, 45.1, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60,61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78,79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96,97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,112, 113, 114, 115, 116, 117, 118, 118.1, 119, 120, 121, 122, 123, 124,125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138,138.1, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151,152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 16.3, 164, 165,166, 167, 168, 169, 170, 171, 171.1, 172, 173, 174, 175, 176, 177, 178,179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192,193, 194, 195, 196, 197, 198, 199, 200, 201, 202; or a mixturecomprising two or more dyes.

[0023] Preferably component a) is present in an amount of 1 to 15, morepreferably 2 to 10 parts of the composition. Component a) may be asingle component or a combination of components, e.g. a mixture of 2, 3or 4 dyes.

[0024] b) The Compounds of Formula (1)

[0025] Preferably R¹ and R² are each independently alkyl, or R¹ and R²together with the N atom to which they are attached from a 5- or6-membered ring. More preferably R¹ and R² are each independentlyC₁₋₆-alkyl, especially ethyl.

[0026] When R¹ and R² together with the N atom to which they areattached form a 5- or 6-membered ring, the ring is preferably anoptionally substituted morpholine, piperazine or piperidine. Preferredoptional substituents are carboxy and sulpho.

[0027] Preferably the total number of carbon atoms in R¹ and R² addedtogether is from 3 to 18, more preferably 3 to 12, especially 3 to 6.

[0028] Ar is preferably phenylene.

[0029] X is preferably a cation, more preferably an alkali metal(especially Na⁺, K⁺ or Li⁺), ammonium or substituted ammonium cation.

[0030] Examples of compounds of Formula (1) include4-chloro-N:N-diethylaniline sulphonic acid,N:N-di-n-hexylaniline-3-sulphonic acid, N-ethyl-N-n-hexylanilinedisulphonic acids, 2-N:N-diethylaminonaphthalene-6-sulphonic acid,2-(N-ethyl-N-benzylamino)-toluene-4-sulphonic acid,2-N:N-diethylaminotoluene-4-sulphonic acid,N-ethyl-N-cyclohexylaniline-sulphonic acid,N-ethyl-N-betahydroxyethylaniline-sulphonic acid,N-ethyl-N-phenylbenzylaminomonosulphonic acid,2-(N-ethyl-N-phenylamino)-ethanesulphonic acid,2-(N-butyl-N-phenylamino)ethanesulphonic acid and4:4′bis(diethylamino)diphenyl-2:2′-disulphonic acid. Because of theirease of manufacture and efficiency as buffers, the preferred compoundsof Formula (1) are the lower N:N-dialkyl-derivatives of metanilic acid(aniline 3-sulphonic acid) and sulphanilic acid (aniline 4-sulphonicacid) especially N:N-diethylmetanilic acid, N:N-diethylsulphanilic acid,or the mixture of the two obtained by the sulphonation of diethylanilinewith oleum. N:N-diethylsulphanilic acid is also known asN:N-diethyl-3-sulphoaminobenzene or DEAS.

[0031] Preferably the compound of Formula (1) is present in an amount of0.2 to 10, more preferably 0.2 to 5, especially 0.2 to 1 parts of thecomposition.

[0032] Preferably the compound of Formula (1) is a buffer, especially abuffer which maintains the pH of the composition between pH 4 to 8.

[0033] c) The Organic Solvent

[0034] The weight ratio of component g) to c) is preferably 99:1 to1:99, more preferably 99:1 to 50:50 and especially 95:5 to 75:25.

[0035] The organic solvent is preferably a water-miscible organicsolvent or a mixture comprising such solvents. Preferred water-miscibleorganic solvents include alkanols such as the C₁₋₆-alkanols, preferablymethanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol,tert-butanol, n-pentanol, cyclopentanol, cyclohexanol andhydroxyethylmorpholine; linear amides, preferably dimethylformamide ordimethylacetamide; ketones and ketone-alcohols, preferably acetone,methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscibleethers; preferably tetrahydrofuran and dioxane; diols, preferably diolshaving from 2 to 12 carbon atoms, for example pentane-1,5-diol, ethyleneglycol, propylene glycol, butylene glycol, pentylene glycol, hexyleneglycol and thiodiglycol and oligo- and poly-alkyleneglycols, preferablydiethylene glycol, triethylene glycol, polyethylene glycol andpolypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol;mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially 2-methoxyethanol,2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol,2-[2-(2-methoxyethoxy)ethoxy]ethanol,2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol and ethyleneglycol monoallylether;cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone,N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclicesters, preferably caprolactone; sulphoxides, preferably dimethylsulphoxide and sulpholane. Preferably the liquid medium comprises waterand 2 or more, especially from 2 to 8, water-soluble organic solvents.

[0036] Especially preferred water-soluble organic solvents are cyclicamides, especially 2-pyrrolidone, N-methyl-pyrrolidone andN-ethyl-pyrrolidone; diols, especially 1,5-pentane diol, ethyleneglycol,propylene glycol, thiodiglycol, diethyleneglycol and triethyleneglycol;mono-C₁₋₄-alkyl and C₁₋₄-alkyl ethers of diols, more preferablymono-C₁₋₄-alkyl ethers of diols having 2 to 12 carbon atoms, especially2-methoxy-2-ethoxy-2-ethoxyethanol; and triols especially glycerol.

[0037] Preferably component c) is present in an amount of 2 to 30 parts,more preferably 5 to 25 parts of the composition.

[0038] d) The Hydrotropic Agent

[0039] Preferably a hydrotropic agent is present in the compositionbecause such agents help to increase storage stability.

[0040] Preferably hydrotropic agents are anionic, cationic, or non-ionicin nature.

[0041] Examples of anionic hydrotropic agents which may be used in thepractice of the invention include salts of benzoic acid, salicylic acid,benzene disulphonic acid, toluene sulphonic acid, xylene sulphonic acid,cymene-sulphonic acid, cinnamic acid, octane sulphonic acid, hexanesulphonic acid, butane sulphonic acid and decane sulphonic acid. Thecation associated with these salts is preferably Na⁺, K⁺, Li⁺ or NH₄ ⁺.

[0042] Examples of suitable cationic hydrotropic agents include, urea,nicotinamide, guanidine hydrochloride, p-amino benzoic acidhydrochloride, procaine hydrochloride, caffeine and salts ofalkylpyridium, alkyltrimethyl ammonium, benzyltrialkyl (C1 to C4)ammonium, and phenyltrimethyl ammonium cations. The anion associatedwith these salts is preferably any of the halides, particularly Cl⁻.

[0043] Examples of non-ionic hydrotropic agents include, Beta-napthaleneethoxylates, caprolactam derivatives, resorcinol and pyrogallol.

[0044] Preferably the hydrotropic agent is a nicotinamide or urea. Morepreferably the hydrotropic agent is a urea.

[0045] Preferably component d) is present in an amount of 0.5 to 20parts of the composition.

[0046] e) The Biocide

[0047] Preferably a biocide is present in the composition because thisprevents microbial spoilage during manufacture, storage and use.Examples of biocides include: isothiazolin-3-ones such as4,5-trimethylene-4-isothiazolin-3-one,2-methyl-4,5-trimethylene-4-isothiozolin-3-one,2-methylisothiazolin-3-one, 5-chloro-2-methylisothiazolin-3-one,2-octylisothiazolin-3-one, 4,5-dichloro-2-octyltisothiazolin-3-one,benzisothiazolin-3-one, 2-butylbenzisothiazolin-3-one and2-methylbenzisothiazolin-3-one; thiazole derivatives such as2-(thiocyanomethylthio)-benzthiazole and mercaptobenzthiazole; nitrocompounds such as tris(hydroxymethyl)nitromethane,5-bromo-5-nitro-1,3-dioxane and 2-bromo-2-nitropropane-1,3-diol;aldehydes and derivatives such as gluteraldehyde (pentanedial),p-chlorophenyl-3-iodopropargyl formaldehyde and glyoxal; guanidinederivatives such as polyhexamethylenebisbiguanide and1,6-hexamethylene-bis[5-(4-chlorophenyl)biguanide]; thiones such as3,5-dimethyltetrahydro-1,3,5-2H-thiodiazine-2-thione; triazinederivatives such as hexahydrotriazine and1,3,5-tri-(hydroxyethyl)-1,3,5-hexahydrotriazine; oxazolidine andderivatives thereof such as bis-oxazolidine; furan and derivativesthereof such as 2,5-dihydro-2,5-dialkoxy-2,5-dialkylfuran; carboxylicacids and the salts and esters thereof such as sorbic acid and the saltsthereof and 4-hydroxybenzoic acid and the salts and esters thereof;phenol and derivatives thereof such as5-chloro-2-(2,4-dichlorophenoxy)phenol, thio-bis(4-chlorophenol) and2-phenylphenol. The biocides may be used singly. Alternatively, two ormore biocides may be used in combination. Preferably the biocide is anisothiazolinone more preferably it is a benzisothiazolinone. It isespecially preferred that the biocide is benzisothiazolin-3-one.

[0048] Preferably component d) is present in an amount of 0.001 to 5parts, more preferably 0.01 to 0.5 parts of the composition. f) TheSurfactant

[0049] Preferably a surfactant is present in the composition. Inaddition to stabilising the composition surfactants can also shorten thedrying time for the composition and enhance penetration into thesubstrate.

[0050] Preferred surfactants are non-ionic, anionic, cationic oramphoteric.

[0051] Examples of non-ionic surfactants include polyoxyethylene nonylphenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylenedodecyl phenyl ether, polyoxyethylene alkyl ethers, polyoxyethylenepolyoxypropylene block copolymers, polyoxyethylene fatty acid esters,sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters,fatty acid alkylolamides, acetylenic diols and the like.

[0052] Examples of anionic surfactants include alkylbenzenesulphonates,alkylphenylsulphonates, alkylnaphthalenesulphonates, formalincondensates of naphthalenesulphonates, higher fatty acid salts,sulphuric ester salts of higher fatty acid esters, sulphonates of higherfatty acid esters, sulphuric acid esters and sulphonates of higheralcohol ethers, alkylcarboxylates of higher alkylsulphonamides,sulphosuccinates and sulphosuccinic acid ester salts.

[0053] Examples of cationic surfactants include primary, secondary andtertiary amine salts, quaternary ammonium salts and the like.

[0054] Examples of amphoteric surfactants include betaine,sulphobetaine, sulphate betaine and the like.

[0055] The surfactants may be used singly or two or more surfactants maybe used in combination.

[0056] Preferably the surfactant comprises an acetylinic diol, e.g. aSurfynol™ surfactant.

[0057] Preferably component f) is present in an amount of 1 to 5 partsof the composition.

[0058] General

[0059] Preferably the composition has been filtered through a filterhaving a mean pore size below 10 μm, more preferably below 2 μm,especially below 1 μm, more especially below 0.45 μm. This filtrationremoves particulate matter which could otherwise block the fine nozzlesfound in many ink-jet printers.

[0060] The composition preferably has a total concentration of divalentmetal ions and trivalent metal ions, other than those bound to the dye,below 1000, more preferably below 100, especially below 20, moreespecially below 10 parts per million by weight relative to the totalweight of ink. Pure composition of this type may be prepared by usinghigh purity ingredients and/or by purifying the composition after it hasbeen prepared. Suitable purification techniques include ultrafiltration,reverse osmosis, ion exchange and combinations thereof.

[0061] In view of preferences outlined above the preferred compositioncomprises:

[0062] a) 1 to 15 parts of a reactive dye;

[0063] b) 0.2 to 5 parts of a compound of Formula (1) as hereinbeforedefined;

[0064] c) 5 to 25 parts of organic solvent;

[0065] d) 0.5 to 20 parts of hydrotropic agent;

[0066] e) 0.001 to 5 parts of biocide;

[0067] f) 0.1 to 5 parts of surfactant; and

[0068] g) 25 to 92.199 parts of water;

[0069] wherein all parts are by weight and a)+b)+c)+d)+e)+f)+g) add upto 100.

[0070] The compositions may be used directly as inks, especially inksfor ink-jet printers, or as concentrates for the preparation of inks.

[0071] The compositions and inks of the invention may of course containfurther ingredients in addition to components a) to g) mentioned above,for example anti-kogation agents, stabilisers, antioxidants etc.

[0072] According to a second feature of the present invention there isprovided a process for forming an image on a substrate comprisingapplying thereto a composition according to the first aspect of thepresent invention by means of an ink-jet printer.

[0073] The ink-jet printer preferably applies the composition to thesubstrate in the form of droplets which are ejected through a smallorifice onto the substrate. Preferred ink-jet printers are piezoelectricink-jet printers and thermal ink-jet printers. In thermal ink-jetprinters, programmed pulses of heat are applied to the composition in areservoir by means of a resistor adjacent to the orifice, therebycausing the composition to be ejected in the form of small dropletsdirected towards the substrate during relative movement between thesubstrate and the orifice. In piezoelectric ink-jet printers theoscillation of a small crystal causes ejection of the composition fromthe orifice. In WO 00/48938 and WO 00/55089 an ink-jet technology isdescribed where ink is ejected from an ink ejection nozzle chamberutilising an electromechanical actuator connected to a paddle or plungerwhich moves towards the ejection nozzle of the chamber for the ejectionof drops of ink from the ejection nozzle chamber.

[0074] Preferably the composition is applied at a temperature in excessof 30° C.

[0075] The substrate is preferably paper, plastic, metal or glass, morepreferably a textile material.

[0076] The textile material may be of natural or synthetic fibresincluding blends thereof. Thus, it may be cellulose, including viscoserayon and regenerated viscose rayon, wool, acrylic, polyamide such asnylon, polyester such as polyethyleneglycolterephthalate orpolyurethane. It is, however, preferably cellulose or a blend thereof.

[0077] The textile material is preferably woven or knitted or in theform of dry or wet laid fibres. It may be in the form of sheets, webs,threads or ready made up garments such as drapes, shirting, toweling,underwear, socks and sheeting.

[0078] Preferably the textile material has been impregnated with acomposition comprising 5% to 50% of a colour enhancing agent, 1% to 5%alkali metal hydroxide, carbonate, bicarbonate or a mixture thereof, 10%to 20% alginate thickener and the balance water, wherein all percentagesare by weight relative to the weight of the composition.

[0079] A preferred colour enhancing agent is as described in U.S. Pat.No. 5,403,358, claim 1, which is incorporated herein by referencethereto.

[0080] A third aspect of the present invention provides a paper, anoverhead projector slide or a textile material printed with acomposition or by means of a process according to the present invention.

[0081] A fourth aspect of the present invention provides an ink-jetprinter cartridge comprising a chamber and an composition, wherein thecomposition is present in the chamber and is as defined in the firstaspect of the present invention as hereinbefore described.

[0082] The invention is further illustrated by the following Examples inwhich all parts and percentages are by weight unless otherwise stated.

EXAMPLES 1 TO 17

[0083] Preparation of Inks

[0084] The inks described in Tables I, II and III were prepared. Numbersquoted refer to the percentage of the relevant ingredient by weight. Allinks were made up to 100% with water.

[0085] The following colorants were used:

[0086] C.I. Reactive Yellow 85

[0087] C.I. Reactive Orange 13

[0088] C.I. Reactive Red 3.1

[0089] C.I. Reactive Red 31

[0090] C.I. Reactive Blue 71

[0091] C.I. Reactive Blue 49

[0092] C.I. Reactive Black 8

[0093] Pro-Jet™ Black R-TX

[0094] Dye 9—A yellow dye of the following structure;

[0095] Dye 10—A red dye of the following structure;

[0096] All dyes were obtained from Avecia Limited apart from C.I.Reactive Blue 49 which was obtained from Atul Ltd. Dyes 9 and 10 do notyet have C.I. designations. “Pro-Jet” is a trade mark of Avecia Ltd.

[0097] Abbreviations used are:

[0098] DEG=diethylene glycol

[0099] PEG=polyethylene glycol

[0100] DEAS=N:N-diethylsulphanilic acid

[0101] Surfynol 465™ is a surfactant comprising an acetylinic diolobtainable from Air Products Ltd, Solsperse™ 2700 is a Beta-naptholethoxylate dispersant obtainable from Avecia Ltd. Proxel™ GXL, is abiocide containing benzisothiazolin-3-one as the active agent alsoobtained from Avecia Ltd. “Surfynol” is a trade mark of Air Products Ltdand “Solsperse” and “Proxel” are trade marks of Avecia Ltd. TABLE I Ink1Ink 2 Ink 3 Ink 4 Ink 5 Ink 6 C.I. Reactive 10.0%  — — — — — Yellow 85Dye 10 — 10.0%  — — — — C.I. Reactive — — 8.5% 8.5% — — Blue 71 Pro-JetBlack — — — — 12.0%   12.0%   R-TX DEG 4.0% 4.0% 5.0% 5.0 15.0%  12.5%   PEG 200 15.0%  13.5%  — — — — Glycerol 1.0% 1.0% — 1.0% 1.0% 1.0%  DEAS 0.5% 0.5% 0.5% 0.5% 0.5%  0.5%  Proxel GXL 0.1% 0.1% 0.1%0.1% 0.1%  0.1%  Surfynol 475 1.0% 1.0% 1.0% 1.0% 1.0%  1.0%  Solsperse2700 — — 1.0% — — —

[0102] TABLE II Ink 7 Ink 8 Ink 9 Ink 10 Ink 11 Dye 9 10.0%  — — — —C.I. Reactive — 10.0%  — — — Orange 13 C.I. Reactive — — 10.0%  — — Red3.1 C.I. Reactive — — — 10.0%   — Blue 71 C.I. Reactive — — — — 10.0% Blue 49 PEG 200 15.0%  15.5%  — — 1.2% DEG 4.0% 4.0% 9.0% 13.0%   4.0%Glycerol 1.0% 1.0% 1.0% 1.0%  1.0% Urea 5.0% 5.0% 5.0% 5.0%  5.0% DEAS0.5% 0.5% 0.5% 0.5%  0.5% Surfynol 475 1.0% 1.0% 2.0% 1.0%  2.0% ProxelGXL 0.1% 0.1% 0.1% 0.1%  0.1%

[0103] TABLE III Ink 12 Ink 13 Ink 14 Ink 15 Ink 16 Ink 17 C.I. 3.0% — —8.0% — — Reactive Red 31 Pro-Jet — 3.0% — — — — Black R-TX C.I. — —10.0%   — — — Reactive Yellow 85 C.I. — — — — 8.0% — Reactive Blue 71C.I. — — — — — 10.0%   Reactive Black 8 DEG 4.0% 4.0% 4.0%  4.0% 4.0%4.0%  PEG 200 4.0% 4.0% 4.0%  4.0% 4.0% 4.0%  Glycerol 1.0% 1.0% 1.0% 1.0% 1.0% 1.0%  Urea 5.0% — — — — — DEAS 0.5% 0.5% 0.5%  0.5% 0.5% 0.5% Proxel GXL 0.1% 0.1% 0.1%  0.1% 0.1% 0.1% 

EXAMPLE 18 AND COMPARATIVE EXAMPLES A TO K

[0104] Stability of an Ink Prepared with Various Buffers

[0105] A number of inks were prepared containing either no buffer (InkA) DEAS of Formula (1) (Ink 18) or one of a variety of alternativecompounds not of Formula (1) (Inks B to K).

[0106] The abbreviations used in Example 18 and Comparative Inks B to Kare:

[0107] PA=Phytic Acid

[0108] DEAS=N:N-diethylsulphanilic acid

[0109] TRIS=tris(hydroxymethyl)aminomethane

[0110] HEPES=4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid

[0111] TES=2-[{tris(hydroxymethyl)-methyl}amino]-1-ethanesulphonic acid

[0112] MOPS=4-morpholinepropanesulphonic acid

[0113] BES=N,N-bis(2-hydroxyethyl)-2-aminoethanesulphonic acid

[0114] BIS-TRIS=2,2-bis(hydroxymethyl)-2,2′,2″-nitrilotriethanol

[0115] MOPSO=Beta-hydroxy-4-morpholinepropanesulphonic acid

[0116] PIPES=1,4-piperazinebis(ethanesulphonic acid)

[0117]HEPPSO=Beta-hydroxy-4-(2-hydroxyethyl)-1-piperazinepropanesulphonic acidmonohydrate

[0118] The ink formulations are shown in Table IV wherein all inks weremade up to 100% with water.

[0119] The inks were then assessed for their pH stability followingstorage for 1 week at 80° C. Results are shown in Table V. TABLE IV Ink18 Ink A Ink B Ink C Ink D Ink E Ink F Ink G Ink H Ink I Ink J Ink K Dye10 10% 10% 10% 10% 10% 10% 10% 10% 10% 10% 10% 10% DEG  4%  4%  4%  4% 4%  4%  4%  4%  4%  4%  4%  4% PEG 200  4%  4%  4%  4%  4%  4%  4%  4% 4%  4%  4%  4% Glycerol  1%  1%  1%  1%  1%  1%  1%  1%  1%  1%  1%  1%PA — — 0.5%  — — — — — — — — — DEAS 0.5%  — — — — — — — — — — — TRIS — —— 0.5%  — — — — — — — — HEPES — — — — 0.5%  — — — — — — — TES — — — — —0.5%  — — — — — — MOPS — — — — — — 0.5%  — — — — — BES — — — — — — —0.5%  — — — — BIS-TRIS — — — — — — — — 0.5%  — — — MOPSO — — — — — — — —— 0.5%  — — PIPES — — — — — — — — — — 0.5%  — HEPPSO — — — — — — — — — —— 0.5% 

[0120] TABLE V Ink pH (t = 0) pH (t = 1 week @80° C.) pH change Ink 187.34 7.45 +0.11 Ink A 7.35 8.08 +0.73 Ink B 7.30 7.81 +0.51 Ink C 7.087.56 +0.48 Ink D 7.09 7.74 +0.65 Ink E 7.20 7.61 +0.41 Ink F 7.16 7.65+0.49 Ink G 7.26 7.56 +0.30 Ink H 7.10 7.72 +0.62 Ink I 7.23 7.62 +0.39Ink J 7.32 7.68 +0.36 Ink K 7.24 7.55 +0.31

[0121] Ink 18 which contains DEAS (a compound of Formula (1)) showssignificantly less pH drift than any of the other inks lacking thiscompound or containing alternative buffers. This decreased tendencytowards pH drift provides enhanced stability of the formulation and lessproblems with crystallisation and colour shift.

EXAMPLES 19 TO 23 AND COMPARATIVE EXAMPLE L

[0122] The inks described in Tables VI were prepared. Numbers quotedrefer to the percentage of the relevant ingredient by weight. All inkswere made up to 100% with water.

[0123] Abbreviations used are:

[0124] DEG=diethylene glycol

[0125] PEG=polyethylene glycol

[0126] DEAS=N:N-diethylsulphanilic acid

[0127] Proxel™ GXL, is a biocide containing benzisothiazolin-3-one asthe active agent obtained from Avecia Ltd. “Proxel” and “Pro-Jet” aretrade marks of Avecia Ltd. TABLE VI Ink 19 Ink 20 Ink 21 Ink 22 Ink 23Reactive 10.0%  Yellow 85 Pro-Jet 10.0%  Magenta 2B-TX Pro-Jet 10.0% Yellow JP-XR Reactive 10.0%  Orange 13 Reactive 10.0%  Red 3.1 DEG 4.0%4.0% 4.0% 4.0%   9% PEG 200 15.0%  13.5%  15.0%  15.5%  Glycerol 1.0%1.0% 1.0% 1.0% 1.0% Urea 5.0% 9.0% 5.0% DEAS 0.5% 0.5% 0.5% 0.5% 0.5%Proxel GXL 0.1% 0.1% 0.1% 0.1% 0.1% Water to to to to to  100%   100%  100%   100%   100% 

[0128] TABLE VII Comparative Ink L Reactive Orange 13 12% Reactive Blue49 Reactive Blue 72 Propylene glycol 20% Water to 100%   

[0129] These inks were evaluated using the following tests:

[0130] Dry Out Test:

[0131] A 5 g sample of ink was placed in a shallow petrie dish measuringabout 50 mm in diameter. The dish was then loosely covered so as toallow free circulation of air around the sample but preventcontamination with dust etc. The sample was allowed to stand at roomtemperature (approximately 20° C.) for 72 hrs. At the end of thisperiod, the sample was sealed to prevent any further drying out. Theappearance of the sample was noted (eg whether or not it was stillfluid, skin formation, appearance of solids). The sample was alsoexamined under a microscope and the presence of any solid material wasnoted. Results are shown in Table VIII. TABLE VIII Ink Results of thedry out test Ink 19 Very Fluid. No solids Ink 20 Very Fluid. No solidsInk 21 Very Fluid. No solids Ink 22 Thick but fluid. No solids Ink 23Very Fluid. No solids Comparative Ink L Very thick liquid with surfaceskin. Amorphous solid present

[0132] Further Inks

[0133] The inks described in Tables IX and X may be prepared whereineach ink is made up to 100% with water. The inks may be applied bythermal or piezo ink-jet printing.

[0134] The following abbreviations are used in Tables IX and X:

[0135] BC=butyl cellusolve

[0136] DEAS=N:N-diethylsulphanilic acid

[0137] DEG=diethylene glycol

[0138] 2P=2-pyrollidone.

[0139] Surfynol 465™ is a surfactant comprising an acetylinic diolobtainable from Air Products Ltd, Proxel™ GXL, is a biocide containingbenzisothiazolin-3-one as the active agent also obtained from AveciaLtd. “Surfynol” is a trade mark of Air Products Ltd and “Proxel” and“Pro-Jet” are trade marks of Avecia Ltd. TABLE IX Ink Ink Ink Ink InkInk Ink Ink Ink Ink Ink 24 25 26 27 28 29 30 31 32 33 34 Pro-Jet YellowJP - XR 10% Pro-Jet Red 2B - TX 10%  2% C I Reactive Blue 15 10%  2% C IReactive Blue 49 10%  C I Reactive Yellow 85 10% 1.1% C I ReactiveOrange 13 10% C I Reactive Red 3.1 10%  0.54%  Pro-Jet Black PX - 2R12.5%   2.0% Ethylene glycol 8.5%   DEG 10% 8% 10%  9% 10% 10% 7% 15% 14%   15% Glycerol 1% 1% 3% 3%   1% 2P 10% 8% 10%  9% 10% 10% 15%  14%  15% BC  2% 2% 5% 2%  2%  2% 2% 2% 5% 5%   2% Surfynol 465  1% 1% 1%  1% 1% 1% 1% 1% 1%   1% Urea  5% 5% 5% 5%  5%  5% 5% 5% 5% 5%   5% DEAS(50%) 0.5%  0.5%   0.5%   0.5%   0.5%  0.5%  0.5%   0.5%   0.5%   0.5%  0.5% Proxel GXL 0.1%  0.1%   0.1%   0.1%   0.1%  0.1%  0.1%   0.1%  0.1%   0.1%   0.1%

[0140] TABLE X Ink Ink Ink Ink Ink Ink Ink Ink Ink Ink Ink 35 36 37 3839 40 41 42 43 44 45 Pro-Jet Yellow JP - XR 10%  Pro-Jet Red 2B - TX 10%2% C I Reactive Blue 15 10%  2% C I Reactive Blue 49 10%  C I ReactiveYellow 85 10% 1.1% C I Reactive Orange 13 10% C I Reactive Red 3.1 10% 0.54 Pro-Jet Black PX - 2R 12.5%   2.0% Propylene glycol 9% 10% 10%  8%10% 10% 4% 6% 14%  13%   14% Glycerol 1% 1% 3% 3%   1% 2P 9% 10% 10%  8%10% 10% 4% 14%  13%   14% BC 2%  2% 5% 2%  2%  2% 2% 2% 5% 5%   2%Surfynol 465 1%  1% 1%  1%  1% 1% 1% 1% 1%   1% Urea 5%  5% 5% 5%  5% 5% 5% 5% 5% 5%   5% DBAS (50%) 0.5%   0.5%  0.5%   0.5%   0.5%  0.5% 0.5%   0.5%   0.5%   0.5%   0.5% Proxel GXL 0.1%   0.1%  0.1%   0.1%  0.1%  0.1%  0.1%   0.1%   0.1%   0.1%   0.1%

1. A composition comprising: a) 0.1 to 30 parts of colorant; b) 0.1 to20 parts of a compound of Formula (1): R¹R²N—Ar—(SO₃X)_(n)  Formula (1) wherein: R¹ is H, alkyl, cycloalkyl or aralkyl and R² is alkyl,cycloalkyl or aralkyl; or R¹ and R², together with the N atom to whichthey are attached, form a 5- or 6-membered ring; Ar is phenylene ornaphthylene; X is H or a cation; and n is 1 or 2; c) 1 to 40 parts oforganic solvent; d) 0 to 20 parts of hydrotropic agent; e) 0 to 5 partsof biocide; f) 0 to 5 parts of surfactant; and g) 1 to 98.8 parts ofwater; wherein all parts are by weight and a)+b)+c)+d)+e)+f)+g) add upto
 100. 2. A composition according to claim 1 wherein component b)comprises N:N-diethylsulphanilic acid.
 3. A composition according to anyone of the previous claims wherein component a) comprises a dye.
 4. Acomposition according to any one of the previous claims whereincomponent a) comprises a reactive dye.
 5. A composition according to anyof the previous claims wherein component d) comprises a urea.
 6. Acomposition according to any of the previous claims wherein component e)comprises an isothiazolinone.
 7. A composition according to any of theprevious claims wherein component f) comprises an acetylinic diol.
 8. Acomposition according to any of the previous claims wherein component a)is present in an amount of 1 to 15 parts.
 9. A composition according toany of the previous claims wherein component b) is present in an amountof 0.2 to 5 parts.
 10. A composition according to any of the previousclaims wherein component c) is present in an amount of 5 to 25 parts.11. A composition according to any of the previous claims whereincomponent d) is present in an amount of 0.5 to 20 parts.
 12. Acomposition according to any of the previous claims wherein component e)is present in an amount of 0.001 to 5 parts.
 13. A composition accordingto any of the previous claims wherein component f) is present in anamount of 0.1 to 5 parts.
 14. A composition according to claim 1comprising: a) 1 to 15 parts of a reactive dye; b) 0.2 to 5 parts of acompound of Formula (1); c) 5 to 25 parts of organic solvent; d) 0.5 to20 parts of hydrotropic agent; e) 0.001 to 5 parts of biocide; f) 0.1 to5 parts of surfactant; and g) 25 to 92.199 parts of water; wherein allparts are by weight and a)+b)+c)+d)+e)+f)+g) add up to
 100. 15. Anink-jet printing ink according to any one of the preceding claims.
 16. Aprocess for forming an image on a substrate comprising applying theretoa composition according to any one of the preceding claims by means ofan ink-jet printer.
 17. A process according to claim 16 wherein thetemperature of application is in excess of 30° C.
 18. A paper, anoverhead projector slide or a textile material printed with acomposition according to any one of claims 1 to 15 by means of a processaccording to claim 16 and claim
 17. 19. An ink-jet printer cartridgecomprising a chamber and a composition wherein the composition ispresent in the chamber and the composition is according to any one ofclaims 1 to 15.